I wanted to use a 3D printed trigger for the BPX. The options I found online for the TiPX were angled too far forward for me, given how the BPX linkage works. So, I designed this trigger. It should work with the safety, though I have not tested with the safety. I know it works for the BPX linkage to fire the marker, though. Some useful points:

1. This trigger is 9mm wide, which seems to move smoothly when the BPX is bolted tightly together. Other 3D printed triggers I found were wider and ended up binding as a result.
2. This trigger has an extended post to connect to the linkage. I found too short of post caused the trigger to twist/slide out of the linkage if pulled too hard.
3. I include the Fusion 360 file with this trigger. The final sketch in the history contains the angle used to define the trigger angle relative to the linkage angle, so it's very easy to adjust (if you have Fusion 360) and print to suit your liking.

Printer settings:

1. PETG
2. 40%+ infill
3. 5-6 wall loops
4. Automatic tree support
5. Auto rotate for best printing
6. I used a 5mm outer brim due to adhesion issues in my environment. This is not required if you don't have adhesion issues.
7. Bambulabs X1C (what I used, and works well with the tolerances in this model)

Parts required:

1. 3x20mm hex head machine screw (for the post to connect into the linkage)
2. 4x22+mm hex head machine screw or 4mm post. I just used a machine screw and cut it off at 22mm. This serves as the post for the trigger to rotate around. I drilled out the BPX post hole slightly to get this to fit, and I found it provided a strong support for the trigger. You can decrease the hold size easily in the model if you prefer a thinner post.